Traveling by Uber and Lyft may just be too convenient.
According to a working paper by researchers at Institute of Transportation at University of California, Davis, use of transportation modes that would reduce air pollution have declined in cities with heavy usage of the ride-sharing apps. Based on surveys conducted in seven major American cities, the researchers found that roughly half of ride-hailing trips would have been made by walking, biking, or public transit—or simply not made at all. And, the introduction of the ride-hailing services decreased public transit use an average of 6%.
“Ride-hailing is currently likely to contribute to growth in vehicle miles traveled in the major cities represented in this study,” the researchers concluded.
Experts have long theorized that on-demand ride-sharing, optimized through algorithms and eventually driverless cars, will help stave off what some experts believe will be dramatic rise in traffic congestion from ballooning urban transportation demand. Lyft and Uber are early experiments in this theory; if they don’t reduce congestion, perhaps ride-sharing isn’t the solution.
It’s not all that surprising that demand for riding in a car has gone up as the apps have made it more convenient. “When the quality of a service goes up, when cost goes down, demand will increase and people will go on trips they didn’t go on before,” Assaf Biderman, an associate director at MIT’s Senseable City Lab and founder and CEO of transportation technology company Superpedestrian.
A July 2017 Scientific American article co-authored by Biderman and his colleague Carlo Ratti predicted what the UC Davis study observed. “The cost of traveling a mile might drop so substantially that people would abandon public transportation,” they wrote (paywall). “That, in turn, could lead to an increase in the number of vehicles in a city—and with that increase, surreal gridlock.”
That doesn’t necessary mean that in the long run ride-sharing won’t help alleviate traffic snarls, says Biderman. “If you get to put more people into the car, you’re making the most effective use of the road,” he says. His solution is to create cars that are ever smaller. “The closer vehicles become in size to our body, the better we’re able to move more people through the street in a given moment,” he says. His company, Superpedestrian, founded in 2012, is trying to commercialize smaller, robotic transportation options.
“Be patient,” he says, and “put pressure” on ride-sharing companies to design their services in the right way. “Ask for the right vehicle,” he says. “Be sure the vehicles are full.”